High-power H2/Br2 fuel cell

Лившиц, В. А.; Ulus, A.; Peled, E.

doi:10.1016/j.elecom.2006.06.021

Cited by 109 publications

(118 citation statements)

References 13 publications

Supporting

Mentioning

115

Contrasting

Unclassified

Order By: Relevance

“…s i, j n j [9] where the reactor or cell stack is assumed to operate at steady state because processes within the reactor are fast compared to the discharge time of the battery. In the material balances, A is membrane area, N i is the moles of species i, ν is an integer that has a value of −1, 0, or 1, i is the current density, F is the Faraday constant, and s i,j is the coupling…”

Section: +mentioning

confidence: 99%

The Influence of Electric Field on Crossover in Redox-Flow Batteries

Darling

Weber

Tucker

et al. 2015

J. Electrochem. Soc.

150

152

View full text Add to dashboard Cite

Transport of active species through the ion-exchange membrane separating the electrodes in a redox-flow battery is an important source of inefficiency. Migration and electro-osmosis have significant impacts on the crossover of reactive anions, cations, and neutral species. In this paper, these phenomena are theoretically and experimentally explored for commercial cation-exchange membranes. The theoretical analysis indicates that plotting the cumulative Coulombic mismatch between charge and discharge as a function of time can be used to assess crossover rates. The relative importance of migration and electro-osmosis over diffusion is quantified and shown to increase with increasing current density and membrane thickness because the contributions of migration and electro-osmosis to ionic flux are independent of membrane thickness and proportional to current density, while diffusion is inversely proportional to membrane thickness and independent of current density. Redox-flow batteries (RFBs) possess compelling attributes for stationary energy storage. In particular, the inherent decoupling of energy and power in RFBs enables the cost effective use of active materials with low energy density.1,2 Energy is stored in redox-active molecules and power is generated by oxidizing and reducing different redox couples at the positive and negative electrodes.3-5 Two promising technologies are the all-vanadium RFB (VRB) and the hydrogen/bromine RFB, where good performances have been demonstrated recently. [6][7][8][9][10][11][12][13][14] Protons in a cation-exchange membrane (CEM) typically carry charge between the two electrodes in these two RFBs. In both systems, movement of reactant or product species from one electrode to the other through the membrane results in inefficiency and reversible capacity loss. 8,15,16 For these reasons it is worthwhile to investigate the causes of crossover, and examination of the two chosen RFBs allows for the study of transport of active cations, anions, and neutral species.The reactions at the negative and positive electrodes in a VRB are:andrespectively. Protons are the primary ionic charge carriers. Because the active species at both electrodes are vanadium ions, transfer from one electrode to the other is less detrimental than it is in other RFBs that have dissimilar active materials at the two electrodes. Vanadium that traverses the separator reacts to form a discharged ion at the opposite electrode. 17 Although imbalances that occur after repeated cycling can be recovered by mixing the electrolytes, vanadium that crosses the membrane represents an inefficiency that is detrimental in applications like grid-scale energy storage where high efficiency is required for economic success.For the hydrogen/bromine RFB, the reactions at the negative and positive electrodes areBr 2 (aq) + 2e 18-21 Br species that enter the negative electrode can be separated from the negative electrolyte and returned to the positive electrolyte without causing permanent decay, in a similar fashion to vanadium in V...

show abstract

Section: +mentioning

confidence: 99%

The Influence of Electric Field on Crossover in Redox-Flow Batteries

Darling

Weber

Tucker

et al. 2015

J. Electrochem. Soc.

150

152

View full text Add to dashboard Cite

show abstract

“…The regenerative hydrogen-bromine (H 2 -Br 2 ) fuel cell was identified as a promising candidate for large scale electrical energy storage due to the rapid kinetics of the H 2 and Br 2 reactions translating to its higher energy conversion efficiency and power density capability. [1][2][3][4][5][6][7][8] Moreover, the abundance of active materials used in this system is an added advantage. The electrochemical reactions associated with the H 2 -Br 2 fuel cell system are shown below.…”

mentioning

confidence: 99%

High Surface Area Carbon Electrodes for Bromine Reactions in H₂-Br₂Fuel Cells

Yarlagadda

Lin

Chong

et al. 2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

In a hydrogen-bromine (H 2 -Br 2 ) fuel cell, the Br 2 reactions don't require precious metal catalysts, hence porous carbon gas diffusion media (GDM) are widely used as electrodes. However, the specific surface areas of the commercial carbon gas diffusion electrodes (GDEs) are quite low and need to be enhanced. In order to improve the active surface area of carbon GDEs, a study was conducted to grow multi-walled carbon nanotubes (MWCNTs) directly on the carbon electrode fiber surface. Both constant and pulse current electrodeposition techniques were used to deposit Co nanoparticles to catalyze the MWCNT growth. The MWCNTs were grown in the presence of a mixture of acetylene, argon, and hydrogen gases using the chemical vapor deposition process. Based on the results obtained from SEM, TEM, and EDX analysis, MWCNT growth following the tip model was confirmed. The results from the multi-step chronoamperometry study have shown that the synthesized carbon GDEs with MWCNTs have 7 to 50 times higher active surface area than that of a plain GDE. The performance of a single layer of the best MWCNT GDE measured in a H 2 -Br 2 fuel cell was found to be equal or slightly higher compared to that obtained using a three-layer plain carbon electrode. Electrical energy storage is required to address the increasing use of intermittent energy sources. The regenerative hydrogen-bromine (H 2 -Br 2 ) fuel cell was identified as a promising candidate for large scale electrical energy storage due to the rapid kinetics of the H 2 and Br 2 reactions translating to its higher energy conversion efficiency and power density capability.1-8 Moreover, the abundance of active materials used in this system is an added advantage. The electrochemical reactions associated with the H 2 -Br 2 fuel cell system are shown below. The bromine electrode in the H 2 -Br 2 fuel cell can be replaced by alternative materials such as vanadium, cesium, chromium or iron. However, the H 2 -Br 2 system is more attractive than the hydrogen-vanadium 9 because its active material (HBr) is inexpensive, its electrode reaction kinetics are much faster, and it has much higher energy density (higher HBr/Br 2 concentrations and no supporting electrolyte required because HBr serves as both the reactive material and electrolyte). On the other hand, cesium is a rare earth element and is very expensive ($10/gram or $300/ounce) making it unsuitable for large scale energy storage. Also, the cesium, chromium, and iron systems have not been explored with a negative hydrogen electrode.While the H 2 reactions currently require the use of precious metal catalysts like platinum, the bromine reactions don't since reasonable exchange current densities can be obtained with carbon materials. 6 Even though the exchange current density of Br 2 reactions on platinum (Pt) is two orders of magnitude higher than that on carbon materials, the corrosivity and toxicity of hydrobromic acid (HBr) and * Electrochemical Society Student Member.* * Electrochemical Society Active Member. * * * Electrochem...

show abstract

“…However, cell resistances are so high because of the very slow oxygen reduction reaction that this potential is not currently exploited due to the resulting low cell voltage. H/Br- [20,21] Energies 2016, 9, 627 13 of 15 and Fe-RFBs [22,23] occupied a similar position because of their similar values. Their material costs are already so low that any further reduction in material costs would have almost no impact on system costs.…”

Section: Influence Of the Bipolar Platesmentioning

confidence: 93%

“…However, cell resistances are so high because of the very slow oxygen reduction reaction that this potential is not currently exploited due to the resulting low cell voltage. H/Br- [20,21] and Fe-RFBs [22,23] The figure shows a number of examples of redox flow batteries at open circuit voltage, although it should be remembered that the actual values can vary due to concentration differences and membrane potentials, though this only applies to the horizontal direction. The vertical deviations can be the result of changing material prices.…”

Section: Influence Of the Bipolar Platesmentioning

confidence: 99%

Techno-Economic Modeling and Analysis of Redox Flow Battery Systems

et al. 2016

View full text Add to dashboard Cite

Abstract:A techno-economic model was developed to investigate the influence of components on the system costs of redox flow batteries. Sensitivity analyses were carried out based on an example of a 10 kW/120 kWh vanadium redox flow battery system, and the costs of the individual components were analyzed. Particular consideration was given to the influence of the material costs and resistances of bipolar plates and energy storage media as well as voltages and electric currents. Based on the developed model, it was possible to formulate statements about the targeted optimization of a developed non-commercial vanadium redox flow battery system and general aspects for future developments of redox flow batteries.

show abstract

High-power H2/Br2 fuel cell

Cited by 109 publications

References 13 publications

The Influence of Electric Field on Crossover in Redox-Flow Batteries

The Influence of Electric Field on Crossover in Redox-Flow Batteries

High Surface Area Carbon Electrodes for Bromine Reactions in H₂-Br₂Fuel Cells

Techno-Economic Modeling and Analysis of Redox Flow Battery Systems

Contact Info

Product

Resources

About

High-power H2/Br2 fuel cell

Cited by 109 publications

References 13 publications

The Influence of Electric Field on Crossover in Redox-Flow Batteries

The Influence of Electric Field on Crossover in Redox-Flow Batteries

High Surface Area Carbon Electrodes for Bromine Reactions in H2-Br2Fuel Cells

Techno-Economic Modeling and Analysis of Redox Flow Battery Systems

Contact Info

Product

Resources

About

High Surface Area Carbon Electrodes for Bromine Reactions in H₂-Br₂Fuel Cells